Satellite communications has experienced impressive demand and growth over the last couple of decades in commercial, governmental, and military environments. Satellite communications have become a prevalent part of data communications throughout the world.
The design of a satellite system, however, poses various challenges with respect to maximization of throughput and associated design issues relating to the optimization of bandwidth usage, power consumption, latency, error rates, failure recovery, and the like. Further, as business models push for ever increasing capacity in a satellite system (e.g., based on the investment expense and time to market for a new satellite system or even an additional satellite), system requirements drive demands for larger and more robust satellite designs. Larger satellites, however, pose even more difficult design challenges, such as in the areas of antenna designs that optimize bandwidth usage and minimize co-channel interference. Detailed traffic studies and forecasts are required for antenna system designs in order to optimize the layout of antenna elements for a beam and frequency reuse pattern that optimizes the capacity of the satellite. Further, such antenna designs generally must be fixed and customized for a particular geographic region in order to design an optimal beam pattern, making them somewhat inflexible for relocation. Also, in cases where traffic patterns are difficult, if not impossible, to forecast, large antenna system designs for such large capacity satellites are correspondingly difficult, if not impossible, to optimize.
Additionally, as the number of beams increases, the challenge, complexity and expense of designing a flexible antenna system that achieves an acceptable level of beam isolation and co-channel interference also increases. In many cases of large satellites, multiple large antenna systems are required to achieve acceptable isolation and co-channel interference. Moreover, as the complexity increases, the expense and time-to-market for a new satellite system also increases. Further, satellite system designs become larger and more complex, the system becomes less forgiving with respect to fault tolerance, which complicates manufacturability and time to manufacture.
What is needed, therefore, is a satellite system architecture that provides for high density capacity allocations in smaller geographic regions. What is further needed through such an architecture is flexibility in capacity allocation and beam footprints for instances where traffic forecasts are difficult or relatively impossible, and where traffic demands significantly vary over time. Additionally, such a satellite system architecture should be less complex and less expensive and time consuming to design and manufacture.